Utero-ovarian blood flow characteristics of pituitary desensitization

BACKGROUND: Down-regulation in assisted reproduction treatment cycles is mo nitored by suppression of ovarian/pituitary hormones and/or measurement of endometrial thickness. METHODS: This prospective longitudinal study reports on utero-ovarian characteristics of pituitary desensitization. A total of 75 patients were recruited; 32 had IVF treatment, 20 frozen-thawed embryo t ransfer cycles and 23 patients were recipients of donated oocytes. All rece ived early follicular-phase down-regulation and had colour flow Doppler vel ocimetry of the utero-ovarian arteries less than or equal to3 days before t he start of menses and after 21 days of gonadotrophin-releasing hormone (Gn RH) analogue treatment. Ovarian volume, endometrial thickness, pituitary an d ovarian hormone concentrations were recorded at each scan. RESULTS: Signi ficant changes (P < 0.05) were noted in these and utero-ovarian vasculature during the down-regulation period, with good correlation between resistanc e index and oestradiol estimations. Neither the type of GnRH analogue nor a ge influenced the changes in utero-ovarian blood flow. Ovarian artery resis tance index was the best Doppler predictor for pituitary suppression and a mean discriminatory cut-off value of 0.867 +/- 0.025 was found to have the highest specificity and positive predictive value. CONCLUSIONS: This study has, for the first time, defined cut-off values for satisfactory pituitary suppression with high positive predictive value and specificity in an early follicular phase long protocol of GnRH analogue down-regulation using colo ur flow Doppler.